Top Voted Answer

Selphy isnt taught by cinnamon, its melody and lara that is taught by cinnamon.to get the event to start where you have to battle some monster selphy takes you too, u will have to keep talking to her until the dialogue on the lines of her wanting to reading this new book, and u (raguna) respond with something on the lines of 'didnt you read this already'. you have to get this dialogue to happen like 3-4 times (it usually appears around once per day if u keep talkin to her), so within 3-4 days time when you enter the library, you'll see selphy being sucked into a book (which is causing her memory loss) you will have the chance to go save before entering and defeating the monsters inside (its ridiculously easy, trust me)After this event finished, u shuld get the 'memory-pic' of selphy on the menu screen and also fulfill the requirement to marry her

Answers

Did you complete all of the events with her and Melody being taught by Cinnamon? I'm not sure if those have any bearing on Selphy's LP events, but I know they did for Cinammon's, so it could easily work both ways.

Okay so I just got this to work myself: you need to have had the conversation about her reading a book already (see one of the other suggested answers), which at 10 LP you probably have had it, then you come to see her IN THE MORNING. I believe it's just like getting her to clean the library and speaking of which you will need to come on a day where it's dirty and books are everywhere because it will trigger the clean library cutsceen if you don't and cancel out the one you want.

you have to get her to talk about the new book she bought and you also should have triggered the part where she cleans the library and it gets messy again. just keep talking to her everyday. To be sure, get the part where she whines that Kanno is not lending her his books, and the rest complaining about her borrowing it. There's also a time when Kanno or Cinnamon is in the library reading by the corner, you should try to trigger that too.I think there are three event conversations for this, but you can only get 1 per day: 1st, she talks about a new book she cant wait to read, without Raguna commenting. 2nd, she still talks about a new book that she cant wait to read, but this time, Raguna comments about it, saying something about her already reading it. 3rd, is the last one about a new book she bought and she cant wait to discover what its about. When you've met all the requirements, the event always shows up right away, 100%. If it doesn't, you've failed to trigger something neccessary.